The bug
Hostile baby bees don't have an attacking animation unlike their adult counterparts. They attack you without flipping themselves upside down to sting you, although they can lose their stinger.
How to reproduce
Spawn a baby bee
Go to survival and hit the baby bee once
The baby bee becomes hostile while getting close to you
→ ❌ The baby bee does not have the sting attacking animation
Confirmed for 19w35a